The tumor vessel targeting agent NGR-TNF controls the different stages of the tumorigenic process in transgenic mice by distinct mechanisms

Geotemporal Fluorophore Biodistribution Mapping of Colorectal Cancer: Micro and Macroscopic Insights

Fluorescence-guided oncology promises to improve both the detection and treatment of malignancy. We sought to investigate the temporal distribution of indocyanine green (ICG), an exogenous fluorophore in human colorectal cancer. This analysis aims to enhance our understanding of ICG's effectiveness in current tumour detection and inform potential future diagnostic and therapeutic enhancements.

METHODS

Fifty consenting patients undergoing treatment for suspected/confirmed colorectal neoplasia provided near infrared (NIR) video and imagery of transanally recorded and ex vivo resected rectal lesions following intravenous ICG administration (0.25 mg/kg), with a subgroup providing tissue samples for microscopic (including near infrared) analysis. Computer vision techniques detailed macroscopic 'early' (<15 min post ICG administration) and 'late' (>2 h) tissue fluorescence appearances from surgical imagery with digital NIR scanning (Licor, Lincoln, NE, USA) and from microscopic analysis (Nikon, Tokyo, Japan) undertaken by a consultant pathologist detailing tissue-level fluorescence distribution over the same time.

RESULTS

Significant intra-tumoural fluorescence heterogeneity was seen 'early' in malignant versus benign lesions. In all 'early' samples, fluorescence was predominantly within the tissue stroma, with uptake within plasma cells, blood vessels and lymphatics, but not within malignant or healthy glands. At 'late' stage observation, fluorescence was visualised non-uniformly within the intracellular cytoplasm of malignant tissue but not retained in benign glands. Fluorescence also accumulated within any present peritumoural inflammatory tissue.

CONCLUSION

This study demonstrates the time course diffusion patterns of ICG through both benign and malignant tumours in vivo in human patients at both macroscopic and microscopic levels, demonstrating important cellular drivers and features of geolocalisation and how they differ longitudinally after exposure to ICG.

Salvage Therapy for Relapsed Malignant Pleural Mesothelioma: A Systematic Review and Network Meta-Analysis

Simple Summary

Malignant pleural mesothelioma (MPM) is an aggressive cancer with limited therapeutic options. Pemetrexed plus platinum is a standard first-line therapy, but options for second-line therapy in patients with relapsed mesothelioma remain controversial. Several drugs were recently introduced to treat relapsed MPM. We conducted a comprehensive systematic review and network meta-analysis to evaluate the efficacy of these drugs according to published randomized controlled trials. Nivolumab alone or nivolumab plus ipilimumab provided significantly longer overall survival (OS), and treatment with nivolumab plus ipilimumab was associated with the best OS based on the surface under the cumulative ranking curve (SUCRA). The network meta-analysis revealed that tremelimumab, vorinostat, chemotherapy (CTX), asparagine–glycine–arginine–human tumor necrosis factor plus CTX, nivolumab alone, and nivolumab plus ipilimumab all produced significant progression-free survival (PFS) benefits compared with placebo, with nivolumab plus ipilimumab ranked first for PFS according to SUCRA.

Abstract

Patients with malignant pleural mesothelioma (MPM) have very poor prognoses, and pemetrexed plus platinum is the standard first-line therapy. However, the second-line therapy for relapsed MPM remains controversial. A comprehensive search was performed to identify randomized controlled trials (RCTs) evaluating various second-line regimens in patients with relapsed MPM. Indirect comparisons of overall survival (OS) and progression-free survival (PFS) were performed using network meta-analysis. Surface under the cumulative ranking curve (SUCRA) values were used to rank the included treatments according to each outcome. Nivolumab alone or nivolumab plus ipilimumab provided significantly longer OS than placebo (hazard ratio (HR): 0.72, 95% confidence interval (CI): 0.55–0.94 for nivolumab alone; HR: 0.54, 95% CI: 0.31–0.92 for nivolumab plus ipilimumab). The best SUCRA ranking for OS was identified for nivolumab plus ipilimumab (SUCRA: 90.8%). Tremelimumab, vorinostat, nivolumab alone, chemotherapy (CTX), asparagine–glycine–arginine–human tumor necrosis factor plus CTX, and nivolumab plus ipilimumab all produced noticeable PFS benefits compared with placebo. Nivolumab plus ipilimumab had the best PFS ranking (SUCRA: 92.3%). Second-line treatment with nivolumab plus ipilimumab provided the OS and PFS outcomes for patients with relapsed MPM.

Role of Immune Checkpoint Inhibitor Therapy in Advanced EGFR-Mutant Non-Small Cell Lung Cancer

Over the last decade, the treatment of advanced non-small cell lung cancer (NSCLC) has undergone rapid changes with innovations in oncogene-directed therapy and immune checkpoint inhibitors. In patients with epidermal growth factor receptor (EGFR) gene mutant (EGFRm) NSCLC, newer-generation tyrosine kinase inhibitors (TKIs) are providing unparalleled survival benefit and tolerability. Unfortunately, most patients will experience disease progression and thus an urgent need exists for improved subsequent lines of therapies. The concurrent revolution in immune checkpoint inhibitor (ICI) therapy is providing novel treatment options with improved clinical outcomes in wild-type EGFR (EGFRwt) NSCLC; however, the application of ICI therapy to advanced EGFRm NSCLC patients is controversial. Early studies demonstrated the inferiority of ICI monotherapy to EGFR TKI therapy in the first line setting and inferiority to chemotherapy in the second line setting. Additionally, combination ICI and EGFR TKI therapies have demonstrated increased toxicities, and EGFR TKI therapy given after first-line ICI therapy has been correlated with severe adverse events. Nonetheless, combination therapies including dual-ICI blockade and ICI, chemotherapy, and angiogenesis inhibitor combinations are areas of active study with some intriguing signals in preliminary studies. Here, we review previous and ongoing clinical studies of ICI therapy in advanced EGFRm NSCLC. We discuss advances in understanding the differences in the tumor biology and tumor microenvironment (TME) of EGFRm NSCLC tumors that may lead to novel approaches to enhance ICI efficacy. It is our goal to equip the reader with a knowledge of current therapies, past and current clinical trials, and active avenues of research that provide the promise of novel approaches and improved outcomes for patients with advanced EGFRm NSCLC.

Tumor vessel co-option probed by single-cell analysis

Tumor vessel co-option is poorly understood, yet it is a resistance mechanism against anti-angiogenic therapy (AAT). The heterogeneity of co-opted endothelial cells (ECs) and pericytes, co-opting cancer and myeloid cells in tumors growing via vessel co-option, has not been investigated at the single-cell level. Here, we use a murine AAT-resistant lung tumor model, in which VEGF-targeting induces vessel co-option for continued growth. Single-cell RNA sequencing (scRNA-seq) of 31,964 cells reveals, unexpectedly, a largely similar transcriptome of co-opted tumor ECs (TECs) and pericytes as their healthy counterparts. Notably, we identify cell types that might contribute to vessel co-option, i.e., an invasive cancer-cell subtype, possibly assisted by a matrix-remodeling macrophage population, and another M1-like macrophage subtype, possibly involved in keeping or rendering vascular cells quiescent.

Tumor Vasculature Targeted TNFα Therapy: Reversion of Microenvironment Anergy and Enhancement of the Anti-tumor Efficiency

Tumor cells and tumor-associated stromal cells such as immune, endothelial and mesenchimal cells create a Tumor Microenvironment (TME) which allows tumor cell promotion, growth and dissemination while dampening the anti-tumor immune response. Efficient anti-tumor interventions have to keep into consideration the complexity of the TME and take advantage of immunotherapy and chemotherapy combined approaches. Thus, the aim of tumor therapy is to directly hit tumor cells and reverse endothelial and immune cell anergy. Selective targeting of tumor vasculature using TNFα-associated peptides or antibody fragments in association with chemotherapeutic agents, has been shown to exert a potent stimulatory effect on endothelial cells as well as on innate and adaptive immune responses. These drug combinations reducing the dose of single agents employed have led to minimize the associated side effects. In this review, we will analyze different TNFα-mediated tumor vesseltargeted therapies in both humans and tumor mouse models, with emphasis on the role played by the cross-talk between natural killer and dendritic cells and on the ability of TNFα to trigger tumor vessel activation and normalization. The improvement of the TNFα-based therapy with anti-angiogenic immunomodulatory drugs that may convert the TME from immunosuppressive to immunostimulant, will be discussed as well.

Nanoparticle Delivery and Tumor Vascular Normalization: The Chicken or The Egg?

Tumor-induced angiogenesis has been a significant focus of anti-cancer therapies for several decades. The immature and "leaky" tumor vasculature leads to significant cancer cell intravasation, increasing the metastatic potential, while the disoriented and hypo-perfused tumor vessels hamper the anti-tumor efficacy of immune cells and prevent the efficient diffusion of chemotherapeutic drugs. Therefore, tumor vascular normalization has emerged as a new treatment goal, aiming to provide a mature tumor vasculature, with higher perfusion, decreased cancer cell extravasation, and higher efficacy for anti-cancer therapies. Here we propose an overview of the nanodelivery approaches that target tumor vasculature, aiming to achieve vascular normalization. At the same time, abnormal vascular architecture and leaky tumor vessels have been the cornerstone for nanodelivery approaches through the enhanced permeability and retention (EPR) effect. Vascular normalization presents new opportunities and requirements for efficient nanoparticle delivery against the tumor cells and overall improved anti-cancer therapies.

Mechanism of Action of the Tumor Vessel Targeting Agent NGR-hTNF: Role of Both NGR Peptide and hTNF in Cell Binding and Signaling

NGR-hTNF is a therapeutic agent for a solid tumor that specifically targets angiogenic tumor blood vessels, through the NGR motif. Its activity has been assessed in several clinical studies encompassing tumors of different histological types. The drug’s activity is based on an improved permeabilization of newly formed tumor vasculature, which favors intratumor penetration of chemotherapeutic agents and leukocyte trafficking. This work investigated the binding and the signaling properties of the NGR-hTNF, to elucidate its mechanism of action. The crystal structure of NGR-hTNF and modeling of its interaction with TNFR suggested that the NGR region is available for binding to a specific receptor. Using 2D TR-NOESY experiments, this study confirmed that the NGR-peptides binds to a specific CD13 isoform, whose expression is restricted to tumor vasculature cells, and to some tumor cell lines. The interaction between hTNF or NGR-hTNF with immobilized TNFRs showed similar kinetic parameters, whereas the competition experiments performed on the cells expressing both TNFR and CD13 showed that NGR-hTNF had a higher binding affinity than hTNF. The analysis of the NGR-hTNF-triggered signal transduction events showed a specific impairment in the activation of pro-survival pathways (Ras, Erk and Akt), compared to hTNF. Since a signaling pattern identical to NGR-hTNF was obtained with hTNF and NGR-sequence given as distinct molecules, the inhibition observed on the survival pathways was presumably due to a direct effect of the NGR-CD13 engagement on the TNFR signaling pathway. The reduced activation of the pro survival pathways induced by NGR-hTNF correlated with the increased caspases activation and reduced cell survival. This study demonstrates that the binding of the NGR-motif to CD13 determines not only the homing of NGR-hTNF to tumor vessels, but also the increase in its antiangiogenic activity.

Vascular targeting of LIGHT normalizes blood vessels in primary brain cancer and induces intratumoural high endothelial venules

High-grade brain cancer such as glioblastoma (GBM) remains an incurable disease. A common feature of GBM is the angiogenic vasculature, which can be targeted with selected peptides for payload delivery. We assessed the ability of micelle-tagged, vascular homing peptides RGR, CGKRK and NGR to specifically bind to blood vessels in syngeneic orthotopic GBM models. By using the peptide CGKRK to deliver the tumour necrosis factor (TNF) superfamily member LIGHT (also known as TNF superfamily member 14; TNFSF14) to angiogenic tumour vessels, we have generated a reagent that normalizes the brain cancer vasculature by inducing pericyte contractility and re-establishing endothelial barrier integrity. LIGHT-mediated vascular remodelling also activates endothelia and induces intratumoural high endothelial venules (HEVs), which are specialized blood vessels for lymphocyte infiltration. Combining CGKRK-LIGHT with anti-vascular endothelial growth factor and checkpoint blockade amplified HEV frequency and T-cell accumulation in GBM, which is often sparsely infiltrated by immune effector cells, and reduced tumour burden. Furthermore, CGKRK and RGR peptides strongly bound to blood vessels in freshly resected human GBM, demonstrating shared peptide-binding activities in mouse and human primary brain tumour vessels. Thus, peptide-mediated LIGHT targeting is a highly translatable approach in primary brain cancer to reduce vascular leakiness and enhance immunotherapy. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A preliminary study on the interaction between Asn-Gly-Arg (NGR)-modified multifunctional nanoparticles and vascular epithelial cells

Previously developed Asn-Gly-Arg (NGR) peptide-modified multifunctional poly(ethyleneimine)–poly(ethylene glycol) (PEI–PEG)-based nanoparticles (TPIC) have been considered to be promising carriers for the co-delivery of DNA and doxorubicin (DOX). As a continued effort, the aim of the present study was to further evaluate the interaction between TPIC and human umbilical vein endothelial cells (HUVEC) to better understand the cellular entry mechanism. In the present investigation, experiments relevant to co-localization, endocytosis inhibitors and factors influencing the internalization were performed. Without any treatment, there was no co-localization between aminopeptidase N/CD13 (APN/CD13) and caveolin 1 (CAV1). However, co-localization between CD13 and CAV1 was observed when cells were incubated with an anti-CD13 antibody or TPIC. As compared with antibody treatment, TPIC accelerated the speed and enhanced the degree of co-localization. TPIC entered HUVEC not only together with CD13 but also together with CAV1. However, this internalization was not dependent on the enzyme activity of CD13 but could be inhibited by methyl-β-eyclodextfin (MβCD), further identifying the involvement of caveolae-mediated endocytosis (CvME). This conclusion was also verified by endocytosis inhibitor experiments.